biology lectures quiz #1

Metabolism

transformation of molecules for own use

development

change over time

reproduction

producing copies of themselves

evolution

genetic chnage between generations

atomic number

identifies element by number of protons in atomic nuclei

periodic table

represents each element by letter symbols, arranged by atomic number

elements that have a known role in out body

- major elements

- lesser elements

- trace elements

our major elements

- oxygen

- carbon

- hydrogen

- nitrogen

- phosphorus

mass of the element =

number of atoms X atomic mass

atomic strcture

- nucleus

-electron shells

- atomic mass

nucleus

center of an atom

protons

positive charge, mass of 1 amu

electron shells

electrons and valence electrons

valence electrons

on the outermost shell

- they interact with atoms

- chemical reactions

determine chemical behaviour of atoms

ions

like atoms, except unequal number of protons and electron's therefore carry + or - charge

cation

atom that has lost an electron = positively charged ion

electrolytes

molecules or atoms (known as salts) that ionize in water and form solutions capable of conducting electrical currents

most abundant electrolytic ions in the body

Na+, Ca2+, Mg2+, Cl-, Po4^3-, and HCO3-

electrolyte imbalance

can result in problems ranging from muscle cramps and brittle bones to coma and even death

free radicals

particles with an odd number of electrons

free radicals are produces by

metabolic reactions, radiation, chemicals

free radicals cause

tissue damage because higky rective

antioxidants

substances tat neutralize free radicals

molecules

particles composed of two or more atoms joined by chemical bonds

molecular formula

itemizes each element present and its quantitu

structural formula

- shows arrangement of atoms

- needed to show structural isomers

chemical bonds

forces thatnhold the different atoms of a molecules together and cause different molecules to be attracted to each other

three most important types of chemical bonds

- ionic bonds

- covalent bonds

- hydrogen bonds

true or false: ionic bonds are weak and dissociate in water

true

true or false: ionic bonds tend to form crystals

true

types of covalent bonds

- singles covalent bond vs. double covalent bond

- nonpolar covalent bond vs. polar covalent bond

single covalent bond

one pair of electrons sgared between atoms

double covalent bonds

two pairs of electrons are shared between atoms

nonpolar covalent bonds

electrons spend equal time about each nucleus

polar covalent bond

electrons spend more time about one nucleus

hydrogen bonds

weal attraction between a slightly positive hydrogen atom in ond molecules and a slightly negative oxygen or nirtrogen atom in another

mixtures

substances that are physically blended but not chemically combined

mixtures can be classified as

- solutions

- colloids

- suspensions

solutions

consist of particles of matter mixed with more abundant substances

colloids

consists of larger particles that also do not settlesout of the ixture when left stading for a long time

suspensions

consist of the largest molecules of the 3 mixtures

acid

- proton donor

- release H+ in water

base

- proton acceptor

- often release OH- in water

buffers

used by-the body to resists changes in pH which could otherwise damper cell structure and function

kinetic energy

energy of motion

chemical energy

potential energy stored in molecular bonds; chemical reactions release this energy

heat

kinetic energy of molecular motion

chemical reactions

a process in whihc a covalent or ionic chemical bnd is formed or broken

a chemical equation shows:

reactants --> products

classes of reactions

- decomposition

- synthesis

- exchange

decomposition reactions

large more compex molecules broken down into 2 or more simpler ones

synthesis reactions

two or more small molecules combine to form a larger more complex molecule

reversible reactions

can proceed in either direction under different circumstamces

the direction is determined by

relative abundnace of substances on each side of the equation

reactions rates are affected by

- concentration

- temp

- catalysts

catalysts

speed up reactions without permanent change to itself

metabolism can be divided into

- catabolism

- anabolism

catabolism

energy releasing decomposition reaction, heat energy often released

anabolism

energy requiring synthesis reaction, energy supplied catabolic reactions

the molecules of life

- inorganic (not unique to living systems)

-organic ( originate in or from living systems)

universal solvent

can dissolve a broader range of substances than any other liquid on earth

heat capacity

the amount of heat energy required to raise the temp of 1g of a particular substance by 1*C

true or false: water stailizes internal temp of the body

true

minerals

- body structure

- activators of organic compunds

- electrolytes for nerve and muscle function

gases

- oxygen and carbon dioxide

- nitric oxide

oxygen and CO2

aerobic respiration

organic chemistry

study of compunds containing carbon

organic molecules of life

- carbohydrates

- lipids

- proteins

- nucleic acids

polymers

series of monomers bonded togther

Hydrolysis (decomposition)

splitting of a polymer by the addition of a water molecule

Carbohydrates

the starches and sugars present in foods, hydrophilic organic molecules

three major monosaccharides

1. glucose

2. galactose

3. fructose

three major disaccharides

1. sucrose

2. lactose

3. maltose

polysaccharides

starch, cellulose and glycogen, long chnains of glucose form these polysaccharides

only dietary polysaccharide that humans are able to digest well

starch

the enzyme that digests starch

amylase (maltose is the products)

glycogen

the energy storage polysaccharide produced by animals

what synthesis glycogen after a meal to maintain blood glucose levels

liver cells

primary carbohydrate function

source of energy that can be relatively quickly mobilized and used for fuel by the body

conjugated carbohydrate

made up of two or more chemically different components

lipids

hydrophobic organic molecule

5 primary types of lipids

1. fatty acids

2. triglycerides

3. phospholipids

4. eicosanoids

5. steroids

fatty acids

- chains of usually 4 to 24 carbon atoms

- carboxyl group on one end and a methtl group on the other

saturated fatty acid

carbon atoms saturated with max # of hydrogen atoms

unsaturated fatty acids

contains C=C bonds that could bond more hydrogen

triglyceride synthesis

three fatty acids bonded to glycerol by dehydration synthesis

function of triglycerides

primarily longer term energy storage, unlimited capacity to store fats on the body

- also insulation and shock absorption for organs

Phospholipids

- amphiphilic character \

- primary component of plasma membranes of all animal cells

amphiphilic

hydrophobic tails, hydrophilic head

Eicosanoids function

chemical signals between cells

steroids

lipid with 17 of its C-atoms arranged in 4 rings

choloesterol

parent steroid, all other steroids are derived from it

True or False: steroids are produced only by animals

true: 85% naturally produces byt our body (liver, 15% derived from our diet

all steroids have

4 ringed structure with variations in the functional groups attached to the rings and the location of double bonds

how many amino acids

20, differ by the R group attached to central carbon

nonpolar R group

hydrophobic

polar R group

hydrophilic

peptides

a polymer of 2 or more amino acides

how are peptides named

for the number of amino acids they contain

dipeptides

2 amino acids